Consider TCP$$s Fast Retransmit optimization $($see Figure $3\mathrm{.}37$ from the text, below$).$ Of course, the sender doesn't know for sure that the segment with sequence # $100$ is actually lost $($it can$$t see into the channel$).$ Can a sender get three duplicate ACKs for a segment that in fact has not been lost? Which of the following statements are true? Suppose a channel can lose, but will not corrupt, messages.